Typewriter with ancillary function control

ABSTRACT

A plurality of ancillary nonprint typewriter functions such as word space, tabulation, backspace and carrier return are at least partially performed by operating members carried by a movingtype-element carrier. The overall mechanism of the typewriter is significantly simplified by enabling selection of individual functions through use of presently existing character selection mechanism in combination with a special nonprint mode selection control.

United States 4 Patent [56] References Cited UNlTED STATES PATENTS 2,339,313 1/1944 Zenner.........................

[72] Inventor John 0.Sc'haefer Lexington, Ky. 21 AppLNo. 886,840

mu w w I17 9 1 2,919,002 12/1959 Palmer......-.. 3,382,963 5/1968 Cralleetal.

[22] Filed Dec. 22, 1969 [45] Patented Oct. 12, 1971 [7 3] Assignee International Business Machines Corporation 3,404,766 l0/l96 8 Castle etal. Armonk, NX, Primary Examiner-William B. Penn Assistant Examiner-Stephen C. Pellegrino Attorneys-Hanifin and Jancin and E. Ronald Coffman [54] TYPEWRITER WITH ANCILLARY FUNCTION gg P D ABSTRACT: A plurality of ancillary nonprint typewriter func- 1 rawmg tions such as word space, tabulation, backspace and carrier return are at least partially performed by operating members carried by a moving-type-element carrier. The overall mechanism of the typewriter is significantly simplified by enabling selection of individual functions through use of presently existing character selection mechanism'in combination with a special nonprint mode selection control.

a 8 4 mums- H3 W- NQ 8 9 2 ul -i 4 4 B .00 m m m m m h u n c u u w m m S L h f C l 0 s m m .m U I F l l. l 2 l 0 5 5 5 l l l PATENTED nun 2 IHYI SHEEI 1 [IF 3 FIG. 1

FIG. 6

JOHN 0. SCHAEFER BY W ATTORNEY PATENTEDnnnzm 3612.239

sum ear 3 PATENIED ucn'zlsn 3.612.239

SHEET 3 [1F 3 TYPEWRITER WITH ANCILLARY FUNCTION CONTROL DISCLOSURE OF THE INVENTION BACKGROUND OF THE INVENTION The primary function of a typewriter is to print characters. However, in addition a typewriter must perform variousnonprint ancillary functions such as interword spacing, backspacing, line return, tabulation, case shift, line index, etc. Traditionally, these ancillary functions have been maintained relatively independent of the printing function, both in mechanism and control, as shown, for example, in U.S. Pat

Nos. 2,879,876 and 2,919,002. lnherently, separation of the print and nonprint typewriter functions requires that .separate power-operating devices be employed to perform these functions. In addition, it has been necessary to provide interlock controls to prevent inconsistent simultaneous operation of the printing and ancillary functions.

Some approaches toward integrating the mechanism for performing print and nonprint functions in a typewriter have been previously proposed, particularly in the teletypewriter art. Examples of these approaches are shown in U.S. Pat. Nos. 2,218,113, 2,339,313, and 1,864,088. It is an object of the present invention to provide a practical embodiment of the broad concept of print and nonprint integration inherent in these early proposals which have not been fully adaptedfor practical use in the typewriter art. A further object of this invention is to provide integration of print and nonprint functions in a relatively simple, wholly mechanical system.

SUMMARY OF THE INVENTION This invention integrates the selection of characters for printing and the selection of one of several ancillary nonprint functions in structure contained in the moving type-element carrier of a typewriter like that disclosed in the aforesaid US. Pat. Nos. 2,879,876 and 2,919,002. All operations of the typewriter are perfonned in sequential cycles defined by a unitary power control clutch to thus eliminate the need forseparate safety interlocks. Power for performing all or part of a function is delivered into the type-element carrier by-the typewriter print shaft that normally drives the type element through a printing stroke. The precisely measured motion that.

is normally delivered into the carrier to select individual characters is employed herein to also select individual performance of one of several nonprint functions. A mode control bail is positioned during operating cycles of the typewriter to select either a normal printing mode or a nonprint mode of operation of the print shaft and the character selection, mechanism,

These and other objects, features and advantages of this in,- vention will be apparent to those skilled in the art from the following morespecific description of an illustrative preferred embodiment of my inventive concepts, wherein reference is made to the accompanying drawing of which:

FIG. 1 is a perspective view of a typewriter constructed in.

accordance with my invention and partially broken away to show several significant internal components thereof,

FIG. 2 is a side elevational view of the typewriter shown in FIG. 1 taken in cross section to show several internal details thereof.

FIG. 3 is a perspective view of a type-element carrier employed in the typewriter of FIG. .1,

FIG. 4 is a bottom plan view of the type-element carrier shown in FIG. 3,

FIG. 5 is a partial side view of a detail of construction of the type-element carrier shown in FIGS. 3 and 4,

FIGS. 6 and 7 are enlarged exploded perspective views showing details of construction of mechanisms shown in FIG. 4, and

FIG. 8' is an enlarged detail view of a construction feature of my typewriter particularly relating to FIG. 2.

Referring now more specifically to the drawing, in FIGS. 1; and 2 there. is shown a typewriter or printer 10 of the general type. more completely described in U.S. Pat. Nos. 2,879,876 and 2,919,002. The typewriter 10 has a frame 11 that supports a horizontally stationary platen 12 for receiving paper or other material to be type upon. A guide track-13 is provided for supporting a type element carrier 14 adjacent the platen 12 for horizontal movement along the writing line. The track 13 is formed by frame-mounted members 15 and 16 which can be simple static rails. However, it is preferred to employ as member 15 a rotatable print shaft. foralsodelivering cyclic power to the carrier 14. Member 16 also serves asan escapement rack or carrier position control member.

The carrier 14 supports a spherical type element 17 that is tilted and rotated to present individual character masters 17a (see FIG. 2) to aprinting position 17b for impact cooperation with the platen. 12. The movement of type element 17 is controlled by a whiffletree selector 18 like that completely disclosed in aforesaid U.S.,Pat'. No. 2,919,002. Selectorlfl is mounted. on the frame 11 and is connected through a flexible tape motion transmission 19 into the carrier 14.

A keyboard or input mechanism 20 includescharacter print keys 21 and function keys such as a'word space-key 70, a tabulation key90, a backspace key and a carrier retumkey'l20. The construction of keyboard 20 is, like that more fully disclosed in U.S. Pat. No. 3,086,635. The details of the keyboard 20 are sown in FIG. 2 as particularly relating to the carrier retum-key and its associated mechanism hereinafter described in greater detail.

Referring now particularly to FIG. 2, depression of any key,

for example the carrier retum-key 120, displaces an encoding 25a to a keyboard'operating filter shaft 26. Power is also delivered through gears 25b and 250 to the print shaft 15.

Rotation of the filter shaft 26 drives the trapped interposer- 22 leftwardly and, through a selected perrnutative group of downwardly projecting selection tabs 27, drives selected bails 28 to a leftward position. The bails 28 are connected as dis closed in U.S. Pat. No. 2,919,002 to the selector mechanism 18 (FIG. 1) whichgenerates a precisely measured amount of bivalued motionxfor'rotating and tilting the type element 17. Since carrier return key 120 is a nonprinting function key, it is provided with an' additional downwardly extending nonprintselecting tab 29 to operate mode selection mechanism 30. Tab 29 acts on a bail. 31 to operate links 32, 33, 34 and 35 to displace a two-position control member or pivoted mode-selecting bail 36 away from stop 36a and against the force of spring 37 to its nonprint control condition as shown in broken lines. Spring-biased latch 38 is urged under projection 39 on link 32 to retain bail 36 inits broken line position. At the end of the cycle, filter shaft 26 pivots latch 38 clockwise to release link 32 and hail 36 to be restored by spring 37 to their normal positions as shown; Had a print character key 21 been depressed, its associated interposer 22 would not have a tab 29 and hail 31 would not have been operated. The mode selector bail 36 thus would have been left in its normal or character printselecting position against the stop 36a. The operation of the typewriter 10 in that event would have been substantially identical to that described in aforesaid U.S. Pat. No. 2,919,002 androtation of shaft 15 would cause printing of the character selected by the perrnutative position of the bails 28.

FIGS. 3 through 7 show mechanism within the carrier 14 that responds to operation of a nonprinting function key such as the carrier retum-key 120, in accordance with the concepts of, this invention. FIG. 3 shows a type-elementrocker member 40 that is pivotally mounted on the carrier 16 by bearings 4! on a stationary'shaft 41a and is urged to 8.. r st position by a spring 42. Rocker 40 supports a bracket or vertical standard 43 on which is pivotally mounted at tilt ring 44 having a typeelement-supporting post 45 thereon. The post 45 and tilt ring 44 are connected respectively through appropriate articulated joints not shown, to differentially positionable selection control means including a rotate pulley 46 for positioning the type element 17 about its rotational axis and a pulley sector or bellcrank 47 for positioning the type element 17 about its horizontal or tilt axis.

Bellcrank 47 is pivoted to the standard 43 by a screw shaft 47a and is connected to the tilt ring 44 by a push link 48. Flexible tapes 19a and 19b of the motion transmission 19 are connected respectively to the rotate pulley 46 and the bellcrank 47. The tapes 19a and 19b are threaded, as partially shown in FIG. 1, over suitably mounted pulleys 19c and 19d, and are attached by a stud 192 (FIG. 3) to the carrier 14. The rotate pulley 46 is also connected to a clock spring, not shown, that retains tension in its associated tape 19a. A spring 49 acts against the bellcrank 47 in opposition to tape 19b to maintain tension in that tape.

The rocker 40 is driven clockwise through a print stroke by a selectively active drive mechanism 50. The drive mechanism 50 primarily includes a print or impact cam 51 that is mounted within the carrier 14 on a sleeve 52 that is slidably keyed to the print shaft and is driven through a complete rotation each operational cycle of the typewriter 10. A cam follower roll 53 is mounted on one end of a drive arm, link, or lever 54 that is pivoted on an axle or fulcrum rod 55. Follower 53 is oscillated vertically with each rotation of the print shaft 15. The other end of lever 54 is forked to slidably receive a pin 56 attached to the rocker 40 for driving the rocker clockwise through a stroke to bring the type element 17 into impact cooperation with the platen 12. A print drive control mechanism 60 (see also FIG. 5) is provided to select print or nonprint operation of lever 54 in response to the position of the bail 36.

As shown in FIG. 4 the fulcrum rod 55 is supported at its right end in a self-aligning bearing 61. The left end of fulcrum rod 55 is mounted on a control arm 62, shown in FIG. 3 and better shown in FIG. 5, by which the fulcrum rod 55 is controllably connected with the mode control bail 36. Normally, control arm 62, is which is pivoted to the carrier 14 by stud 63, is also restrained at its right end by a latch member 64. In this restrained condition the fulcrum rod 55 acts as a fixed pivot and power is transmitted from cam 51 through lever 54 to the rocker 40. As particularly shown in FIG. 5, the mode control bail 36 is operative to displace a connecting rod 65 rightwardly against spring 66 to release the latch arm 64 from the control arm 62 thereby leaving the left end of fulcrum rod 55 (see FIG. 4) in a condition where it is supported only by a spring 67. It can now be seen that rotation of the cam 51 will be ineffective to transfer power to the rocker 40 since the pivot provided by fulcrum rod 55 is no longer fixed but will yield as the lever 54 oscillates. By this means the rotation of the print shaft that normally accompanies each operation of cycle clutch 25 is controlled to generate no printing stroke of the rocker 40.

The carrier 14 is normally urged in the letter feeding direction by a main spring 71 (FIG. 1) acting through a cord or cable 72 (FIG. 4). Motion of the carrier 14 is resisted by an escapement pawl component 73 that engages a letter spacedefining tooth 74 of the escapement rack 16. The escapement pawl 73 is pivotally mounted on a post 75 connected to plate 76 on the carrier 14. A clearer view of these parts is shown in FIG. 6. Forwardor letter-feed movement of the carrier 14 is produced by lifting the pawl 73 from the rack 16, allowing main spring 71 to advance the carrier 14, then dropping the pawl 73 into a succeeding tooth 74 of the rack 16. A backspace pawl component 101 also engages the rack 16 and is lifted therefrom along with the escapement pawl 73.

Within the carrier 14 is an escapement or pawl lift mechanism 77 that is operated from a cam 80 mounted on the sleeve 52. Cam 80 drives a multifunction drive member 81 rearwardly (upwardly in FIG. 4) against a restore spring 82 upon each rotation of the print shaft 15. Normally, the drive member 81 is in its pawl lift position 83 and its rearward motion is enabled to be delivered through downwardly extending tabs 73a and 101a (see also FIG. 6) respectively to the escapement pawl 73 and the backspace pawl 101 to lift these pawls from their engagement with the rack 16 thereby allowing the carrier 14 to be displaced leftwardly by the force of the carriage drive main spring 71. Continued rotation of cam allows the spring 82 to return drive member 81 forwardly thereby replacing the escapement pawl 73 and backspace pawl 101 into the rack 16, but in the succeeding tooth 74 thereof, thus defining a letter space increment of motion. While this function is normally performed during each printing operation of the typewriter 10, it is also desirable that this function be performed for spacing between adjacent words.

Selection of interword space upon depression of space bar 70 is accomplished by an interposer like 22 (see FIG. 2) having a projection like 29 for displacing the bail 36 to the noprint position. The interposer will also have a proper contingent of selection tabs 27 for selecting no rotate or tilt motion of the type element 17. Drive member 81 thus goes through its normal motion to produce a letter space but no printing occurs.

Certain functions such as case shift and line index are performed principally externally of the carrier 14. It is desirable however that control of these functions be obtained from the keyboard 20 through interposers like 22 to insure complete sequential cyclic operation of the typewriter. U.S. Pat. application, Ser. No. 781,790, filed Dec. 6,1968 and entitled, Cyclically Operable Typewriter, discloses a line space index mechanism controlled by a keyboard like keyboard 20 herein. U.S. Pat. application, Ser. No. 837,849, filed June 30, 1969 entitled, "Method and Apparatus for Shifting a Typing Element, discloses a case shift mechanism that is controlled from a keyboard like 20 herein. One factor common to both of these previously filed applications is the requirement that the keyboard 20 generate a machine cycle of operation through cycle clutch 25, and that both escapement of the carrier 14 and impact of the type element 17 be suppressed. Mechanism for suppressing the type-element impact has been discussed above. The present mechanism also provides operating mechanism for inhibiting the normal operation of the letter feed-operating mechanism 77 by disabling the connection between the drive member 81 and the downwardly extending tabs 73a and 101a of the escapement pawl 97 and backspace pawl 101 respectively. This separation is effected by operation of the bail 36 and control of the selector mechanism 18 by keyboard 20 to select a three-unit counterclockwise rotation of the type element 17. During the machine cycle, pulley 46 will be rotated substantially 45 counterclockwise (see FIG. 4) and will carry with it a transfer member 84 (see also FIG. 7) having a pair of pins 85 thereon. Bail 36 displaces a longitudinally slidable enabling member 86 rearwardly to locate its end projection 87 in the path of the rearward pin 85. During print operations pin 85 merely rotates past the end projection 87. During the nonprint cycles however, rotation of the pulley 46 acts through pin 85 and enabling member 86 to pivot the drive member 81 counterclockwise about its mounting post 88 to a space inhibit position 89 where its rearward end 89a is separated laterally from the downwardly extending pawl tabs 73a and 1010. As the print shaft 15 rotates, cam 80 will move drive member 81 rearwardly, but this motion will be ineffective to lift the pawls 73 and 101 from the rack 16.

Tabulation is perfonned under the control of a tab lever, or component member 91, see FIGS. 4 and 6, that is slidably mounted on the post 75 and is urged leftwardly in FIG. 4 by a spring 91a. A control tab 92 on the tab lever 91 acts against a side edge 73b (FIG. 6) of the escapement pawl 73 as well as a side edge of the backspace pawl 101. Thus, pivoting tab lever 91 clockwise about post 75 will lift the escapement and backspace pawls 73 and 101 from the rack 16 to initiate rapidtabulating motion of the carrier 14 by the main spring 71. A spring-biased pivoted latch 93 drops under lip 94 of the tab lever 91 to retain it against restore movement by the spring 91a. Pivoting of tab lever 91 also projects a sensing stop tooth 95 of the tab lever 91 into horizontal alignment with any tab stops 96 (FIG. 4) that have been set. Upon encountering a set tab stop 96, tab lever 91 will be driven rightwardly in FIG. 4. Control tab 92 moves beyond escapement pawl side edge 73b thus allowing spring 730 to move pawl 73 into the rack 16 to arrest the carrier 14. Also, rightward movement of tab lever 91 moves lip 94 off of the latch 93'to allow restoration of the tab lever 91 and the backspace pawl 101 by tab lever spring 91a. The details of the tabulation mechanism thus far described are well known to those skilled in the art.

It is thus seen that performance of a tabulation operation requires only rearward pivoting of the tab lever 91. This is accomplished in my invention upon depression of tab key 90 by displacing nonprint bail 36 and selecting five units of counterclockwise motion of rotate pulley 46. Pin 85 acts through enabling member 86 to pivot drive member 81 to a tabulate position 97. Rotation of cam 80 now brings a ledge 98 on member 81 into engagement with stud 99 on the tab lever 91 to lift the tab lever to its projected latched position.

A backspace-operating mechanism 102 is also contained within the carrier 14. The backspace pawl or component member 101 normally engages teeth 74 of the escapement rack 16 which provides a reaction surface for generating backspace motion. The backspace pawl 101 is biased into the rack 16 by a light spring 103 and is slidable on the post 75 (see also FIG. 6). A backspace drive member 104 acts through its output end 105 against a downwardly extending tab 10111 of the backspace pawl 101. The drive member 104 extends along the underside of the carrier 14 to the vicinity of the print shaft and the noprint-control bail 36. A backspace cam 106 is mounted on the sleeve 52 for rotation therewith. The backspace drive member'l04 includes a cam follower 107 which is moved by the bail 36 into opposition with the contoured face 108 of cam 106 during each nonprint cycle. Rearward movement of the drivemember 104 by bail 36 also displaces a fulcrum projection 109 rearwardly toward the escapement rack 16.

The backspace function is selected by controlling the selector 18 (FIG. 1) by an appropriately configured interposer like 22 (FIG, 2) to select three units of tilt motion and three units of counterclockwise rotate motion of the type element 17. The rotate motion will cause drive member 81 to move to its pawl lift inhibit position 89 (FIG. 6;) A function selection control or enabling member 110 is freely pivoted on rotate shaft 111 (FIG. 7) and is urged clockwise in FIG. 4 by a spring 112. As shown in FIG. 3, an upper end portion 113 of control member 110 bears against a pin 114 on the tilt bellcrank 47 thus resisting the urging of spring 112. The selection of three units of tilt motion thus allows end tab 115 of control member 110 to move forwardly toward fulcrum projection 109. C0- cyclic positioning of bail 36 to its-nonprint position and selection of three units of tilt motion will thus align end tab 115 with fulcrum projection 109 to prevent projection 109 from moving rightwardly. The cyclic rotation of print shaft 15 will cause follower 107 to be driven rightwardly, pivoting drive member 104 about the fulcrum projection 109 thereby driving the output end 105 against the backspace pawl 101 which is held stationary by the rack 16. This motion effectively drives the carrier 14 rightwardly through an increment measured by the rise on backspace cam 106. The escapement pawl 73 moves rightwardly by camming outwardly against its spring 73c over a rack tooth 74 with which it develops a new-holding engagement. Continued rotation of the cam 106 allows the drive member 104 to be restored to its original position by a bias spring 116 and also allows the backspace pawl restore spring 103 to return the backspace pawl 101 over a rack tooth 74 to a position equivalent to that shown in FIG. 5. When a nonbackspace, nonprint function is selected, member 104 is allowed to float about its window 117 that loosely surrounds carrier mounted pin 118. Thus no motion is transmitted to output end 105.

' tion provides for use of the multifunctiondrive member 81 to lift the escapementpawl 73 and backspace pawl 101 fromthe rack 16 during a carrier return operation. The mechanism for performing this function is best seen in FIG. 2 wherein carrier return-key 120 and its adjuvant components are shown. Depression of carrier return-key 120 initiates a normal keyboard cycle as described above, which due to the interposer tab 29 selects the nonprint position for mode control bail 36. The interposer selection tabs 27 are coded to select zero rotate of pulley 46 to thereby leave drive member 81 in its pawl lift position 83. In addition, an elongated control tab 121 drives a bellcrank 122 counterclockwise through pin 12211 to pivot the bellcrank about stud l22b to place a fulcrum point or abutment end 123 in alignment with the lower end 124 of a floating lever clutch control link 125. Ends 123 and 124 are complementarily hook shaped to maintain themselves in engagement until the end of the cycle. Rotation of filter shaft 26, as occurs during any keyboard cycle, drives carrier return control cam 126 to pivot the floating lever counterclockwise about the fulcrum provided by abutment 123-Leftward movement of the floating lever 125 operates the carrier return clutch (not shown) through a connecting link 127. In addition, lever 125 pulls a second connecting link 128 to rotate bellcrank 128a and through spring 128b displace a cycle control link 129 to a clockwisespivoted position wherein a nose portion 129a thereof lies in the path of a clutch arbor ledge 24a. The clutch arbor 24 will thus. be allowed to rotate only through a portion of its total stroke. When the nose5129a intercepts arbor ledge 24a the cycle will be thus interrupted at an intermediate point. The condition of thetypewriter 10 at this intermediate point is as follows: Latch 38 is holding bail 36 in its broken line position. Bellcrank end 123 is engaged with lever 125 and the cam 126 has been rotated to activate the carrier return clutch to cause driving of the carrier 14 toward the left margin. Print shaft 15 has rotated to an intermediate position where drive member 81 has been driven rearwardly by cam 80 and has lifted the escapement pawl 73 and the backspace pawl 101 from the rack 16 to prevent them from ratcheting over the rack teeth 74.

The left margin of the writing line is defined by a margin stop device 130 (FIG. 8.) The margin stop 130 is coupled to a margin rack 131 that is movable leftwardly against a spring 132 in a manner well known in the art. When carrier 14 encounters stop 130 by its counterstop 133, rack 131 is driven leftwardly to pivot a bellcrank 134 that pulls a lift linkage that is connected to the bellcrank 129 (FIG. .2) in overpowering opposition to the tensioning force in spring 1728b. Bellcrank 129 is thus displaced counterclockwise about its pivot 12% to release the clutch arbor 24 and allow completion of the cycle previously commenced. As the cycle is completed, print shaft 15 will rotate to its home position carrying with it the cam'80 and allowing restoration of the drive member 81 to return the escapement pawl 73 and backspace pawl 101 to a holding position in the rack 16.-

While a preferred embodiment of my invention hasbeen described in detail for purposes of illustration, those skilled in the art will recognize that the inventive concepts described herein are not limited to this embodiment. Various typewriter functions other than those described can be similarly controlled and other selection mechanism can be employed without departing from the full teachings of my invention. My invention is thus to be limited only by the scope of the following claims.

1. A printer having a frame, a movable type-element carrier, a type element movably supported onsaid carrier, cyclically operable power means mounted on said. frame and operably connected into said carrier for delivering a predetermined increment of motion thereto, selectively .active .drive means operatively connected with said power means for. moving said type element through a printing stroke an input mechanism for sequentially selecting character print-and nonprint operations of the printer, and a differentially positionable selection control means mounted on said carrier for positioning said type element to different operative positions thereof, wherein the improvement comprises:

mode selection means including a two-positioned control member responsive to individual operation selection by said input mechanism for correspondingly selecting either a printing mode in one position thereof, or a nonprinting mode in the other position thereof, said mode selection means further including drive control means for selecting printing stroke movement of said type element by said drive means only during cycles of said power means wherein said two-position control member is in its one position,

first operating means responsive to cocyclic positioning of said two-position control member in its other position and said selection control means in a first predetermined operative position for performing a first ancillary nonprint function, and

second operating means responsive to cocyclic positioning of said two-position control member in its other position and said selection control means in a second predetermined operative position for performing a second ancillary nonprint function.

2. A printer as defined in claim 1 further having letter space means that is normally operableupon each operation of said cyclically operable power means, and wherein:

said first operating means comprises means for inhibiting operation of said letter space means.

3. A printer as defined in claim 1 having escapement pawl means movably mounted on said carrier, a carrier position control member mounted on said frame adjacent said escapement pawl means, means urging said carrier in one direction relative to said carrier position control member, spring means normally positioning said escapement pawl means in operative engagement with said carrier position control member for resisting movement of said carrier by said urging means, and wherein:

said second operating means comprises means for separating said pawl means from said carrier position control member.

4. A printer as defined in claim 1 wherein:

said first operating means comprises means for forward spacing said carrier by letter space increments, and

said second operating means comprises means for inhibiting operation of said first operating means.

5. A printer as defined in claim 1 further comprising:

third operating means responsive to cocyclic positioning of said two-position control member in its other position and said selection control means in a third predetermined operative position for performing a third ancillary nonprint function.

6. A printer as defined in claim 5 wherein:

said first operating means comprises means for backspacing said carrier in letter space increments,

said second operating means comprises means for forward spacing said carrier by letter space increments, and

said third operating means comprises means for inhibiting operation of said second operating means.

7. A printer as defined in claim 5 wherein:

said first operating means comprises means for backspacing said carrier in letter space increments,

said second operating means comprises means for forward spacing said carrier by letter space increments, and

said third operating means comprises means for tabulating said carrier to a predetermined position along a writing line.

8. A printer as defined in claim 1 wherein said first operating means comprises means for backspacing said carrier in letter space increments.

9. A printer as defined in claim 8 wherein said second operating means comprises means for forward spacing said carrier by letter space increments.

10. A printer as defined in claim 8 further having letter space means that is normally operable upon each operation of said cyclically operable power means and wherein:

said second operating means comprises means for inhibiting operation of said letter space means.

111. A printer having a frame. a movably mounted type-element carrier, a type element movably supported on said carrier, cyclically operable power means mounted on said frame and operably connected into said carrier for delivering a predetermined increment of motion thereto, selectively active drive means operatively connected with said power means for moving said type element through a printing stroke, an input mechanism for sequentially selecting character print and nonprint operations of the printer, and differentially positionable selection control means mounted on said carrier for positioning the said type element to different operative positions thereof, wherein the improvement comprises:

mode selection means including a two-position control member responsive to individual operation selection by said input mechanism for correspondingly selecting either a printing mode in one position thereof or a nonprinting mode in the other position thereof, said mode selection means further including drive control means for selecting printing stroke movement of said type element by said drive means only during cycles of said power means wherein said two-position control member is in its one position,

letter space means normally operable upon each operation of said cyclically operable power means for advancing said carrier by letter space increments, and

operating means responsive to cocyclic positioning of said two-position control member in its other position and said selection control means in a first predetermined operative position for inhibiting operation of said letter space means.

12. A printer having a frame, a platen supported by said frame, track means supported on said frame adjacent said platen, a carrier movably supported on said track means for letter-feeding movement therealong, a type element having a plurality of character masters thereon presentable for printing in different operative positions of said type element, means supporting said type element on said carrier, a shaft connected to said carrier, cyclically operable power means mounted on said frame and connected to said shaft for rotating said shaft through a predetermined motion increment, selectively active drive means operatively connected with said power means for causing, when active, impact cooperation between said type element and said platen, an input mechanism for sequentially selecting character print and nonprint operations of the printer, differentially positionable selection control means mounted on said carrier for positioning said type element to different operative positions thereof, selector means movably mounted on said frame and displaceable to a plurality of positions in response to said input mechanism, and motion transmission means interconnecting said positionable selection control means with said selector means for receiving motion therefrom, wherein the improvement comprises:

mode selection means including a two-position control member responsive to individual operation selection by said input mechanism for correspondingly selecting either a printing mode in one position thereof or a nonprinting mode in the other position thereof, said mode selection means further including drive control means for selecting said impact cooperation between said type element and said platen by said drive means whenever said two-position control member is in its one position and for selecting no impact cooperation between said type element and said platen during any cycle of said power means wherein said two-position control member is in its other position, first operating means cooperable with said shaft for performing a first ancillary nonprint function and including at least one first function component member mounted on said carrier, and first enabling means responsive to cocyclic positioning of said two-position control member in its other position and said selection control means in a first predetermined operative position for causing operation of said first operating means, and

second operating means cooperable with said shaft for performing a second ancillary nonprint function and including at least one second function component member mounted on said carrier, and second enabling means responsive to cocyclic positioning of said two position control member in its other position and said selection control means in a second predetennined operative position for causing operation of said second operating means.

13. A printer as defined in claim 12 having escapement pawl means movably mounted on said carrier, a carrier position control member mounted on said frame adjacent said escapement pawl means, means urging said carrier along said track means in one direction relative to said carrier position control member, spring means normally positioning said escapement pawl means in operative engagement with said carrier position control member for resisting movement of said carrier by said urging means, and wherein:

said first operating means comprises means for separating said pawl means from said carrier position control member.

14. A printer as defined in claim 12 wherein said input mechanism comprises a manually operable keyboard; said two-position control member comprises a pivoted bail extending along said track means for cooperating with said carrier in any position thereof; said drive means comprises lever means cooperably engaging a cam mounted on said shaft, and said type-element support means; and said drive control means comprises a fulcrum member for restraining movement of said lever means to pivotal movement thereabout, and means operatively connecting said fulcrum member with said bail for selectively conditioning said fulcrum member to be either effective or noneffective.

15. A printer as defined in claim 12 wherein said first operating means comprises means for backspacing said carrier in letter space increments.

16. A printer as defined in claim 15 wherein said second operating means comprises means for forward-spacing said carrier by letter space increments.

17. A printer as defined in claim 15 having escapement pawl means movably mounted on said carrier, a carrier position control member on said frame adjacent said escapement pawl means, means urging said carrier along said track means in one direction relative to said carrier position control member, spring means normally positioning said escapement pawl means in operative engagement with said carrier position control member for resisting movement of said carrier by said urging means, and wherein:

said second operating means comprises means for separating said pawl means from said carrier position control member. 

1. A printer having a frame, a movable type-element carrier, a type element movably supported on said carrier, cyclically operable power means mounted on said frame and operably connected into said carrier for delivering a predetermined increment of motion thereto, selectively active drive means operatively connected with said power means for moving said type element through a printing stroke, an input mechanism for sequentially selecting character print and nonprint operations of the printer, and a differentially positionable selection control means mounted on said carrier for positioning said type element to different operative positions thereof, wherein the improvement comprises: mode selection means including a two-positioned control member responsive to individual operation selection by said input mechanism for correspondingly selecting either a printing mode in one position thereof, or a nonprinting mode in the other position thereof, said mode selection means further including drive control means for selecting printing stroke movement of said type element by said drive means only during cycles of said power means wherein said two-position control member is in its one position, first operating means responsive to cocyclic positioning of said two-position control member in its other position and said selection control means iN a first predetermined operative position for performing a first ancillary nonprint function, and second operating means responsive to cocyclic positioning of said two-position control member in its other position and said selection control means in a second predetermined operative position for performing a second ancillary nonprint function.
 2. A printer as defined in claim 1 further having letter space means that is normally operable upon each operation of said cyclically operable power means, and wherein: said first operating means comprises means for inhibiting operation of said letter space means.
 3. A printer as defined in claim 1 having escapement pawl means movably mounted on said carrier, a carrier position control member mounted on said frame adjacent said escapement pawl means, means urging said carrier in one direction relative to said carrier position control member, spring means normally positioning said escapement pawl means in operative engagement with said carrier position control member for resisting movement of said carrier by said urging means, and wherein: said second operating means comprises means for separating said pawl means from said carrier position control member.
 4. A printer as defined in claim 1 wherein: said first operating means comprises means for forward spacing said carrier by letter space increments, and said second operating means comprises means for inhibiting operation of said first operating means.
 5. A printer as defined in claim 1 further comprising: third operating means responsive to cocyclic positioning of said two-position control member in its other position and said selection control means in a third predetermined operative position for performing a third ancillary nonprint function.
 6. A printer as defined in claim 5 wherein: said first operating means comprises means for backspacing said carrier in letter space increments, said second operating means comprises means for forward spacing said carrier by letter space increments, and said third operating means comprises means for inhibiting operation of said second operating means.
 7. A printer as defined in claim 5 wherein: said first operating means comprises means for backspacing said carrier in letter space increments, said second operating means comprises means for forward spacing said carrier by letter space increments, and said third operating means comprises means for tabulating said carrier to a predetermined position along a writing line.
 8. A printer as defined in claim 1 wherein said first operating means comprises means for backspacing said carrier in letter space increments.
 9. A printer as defined in claim 8 wherein said second operating means comprises means for forward spacing said carrier by letter space increments.
 10. A printer as defined in claim 8 further having letter space means that is normally operable upon each operation of said cyclically operable power means and wherein: said second operating means comprises means for inhibiting operation of said letter space means.
 11. A printer having a frame. a movably mounted type-element carrier, a type element movably supported on said carrier, cyclically operable power means mounted on said frame and operably connected into said carrier for delivering a predetermined increment of motion thereto, selectively active drive means operatively connected with said power means for moving said type element through a printing stroke, an input mechanism for sequentially selecting character print and nonprint operations of the printer, and differentially positionable selection control means mounted on said carrier for positioning the said type element to different operative positions thereof, wherein the improvement comprises: mode selection means including a two-position control member responsive to individual operation selection by said input mechanism for correspondingly selecting either a printing mode in one position thereof or a nonprinting mode in the other position thereof, said mode selection means further including drive control means for selecting printing stroke movement of said type element by said drive means only during cycles of said power means wherein said two-position control member is in its one position, letter space means normally operable upon each operation of said cyclically operable power means for advancing said carrier by letter space increments, and operating means responsive to cocyclic positioning of said two-position control member in its other position and said selection control means in a first predetermined operative position for inhibiting operation of said letter space means.
 12. A printer having a frame, a platen supported by said frame, track means supported on said frame adjacent said platen, a carrier movably supported on said track means for letter-feeding movement therealong, a type element having a plurality of character masters thereon presentable for printing in different operative positions of said type element, means supporting said type element on said carrier, a shaft connected to said carrier, cyclically operable power means mounted on said frame and connected to said shaft for rotating said shaft through a predetermined motion increment, selectively active drive means operatively connected with said power means for causing, when active, impact cooperation between said type element and said platen, an input mechanism for sequentially selecting character print and nonprint operations of the printer, differentially positionable selection control means mounted on said carrier for positioning said type element to different operative positions thereof, selector means movably mounted on said frame and displaceable to a plurality of positions in response to said input mechanism, and motion transmission means interconnecting said positionable selection control means with said selector means for receiving motion therefrom, wherein the improvement comprises: mode selection means including a two-position control member responsive to individual operation selection by said input mechanism for correspondingly selecting either a printing mode in one position thereof or a nonprinting mode in the other position thereof, said mode selection means further including drive control means for selecting said impact cooperation between said type element and said platen by said drive means whenever said two-position control member is in its one position and for selecting no impact cooperation between said type element and said platen during any cycle of said power means wherein said two-position control member is in its other position, first operating means cooperable with said shaft for performing a first ancillary nonprint function and including at least one first function component member mounted on said carrier, and first enabling means responsive to cocyclic positioning of said two-position control member in its other position and said selection control means in a first predetermined operative position for causing operation of said first operating means, and second operating means cooperable with said shaft for performing a second ancillary nonprint function and including at least one second function component member mounted on said carrier, and second enabling means responsive to cocyclic positioning of said two position control member in its other position and said selection control means in a second predetermined operative position for causing operation of said second operating means.
 13. A printer as defined in claim 12 having escapement pawl means movably mounted on said carrier, a carrier position control member mounted on said frame adjacent said escapement pawl means, means urging said carrier along said track means in one direction relative to said carrier position control member, spring means normally positioning said escapement pawl means in operative engagement with said carrier position control member for resistIng movement of said carrier by said urging means, and wherein: said first operating means comprises means for separating said pawl means from said carrier position control member.
 14. A printer as defined in claim 12 wherein said input mechanism comprises a manually operable keyboard; said two-position control member comprises a pivoted bail extending along said track means for cooperating with said carrier in any position thereof; said drive means comprises lever means cooperably engaging a cam mounted on said shaft, and said type-element support means; and said drive control means comprises a fulcrum member for restraining movement of said lever means to pivotal movement thereabout, and means operatively connecting said fulcrum member with said bail for selectively conditioning said fulcrum member to be either effective or noneffective.
 15. A printer as defined in claim 12 wherein said first operating means comprises means for backspacing said carrier in letter space increments.
 16. A printer as defined in claim 15 wherein said second operating means comprises means for forward-spacing said carrier by letter space increments.
 17. A printer as defined in claim 15 having escapement pawl means movably mounted on said carrier, a carrier position control member on said frame adjacent said escapement pawl means, means urging said carrier along said track means in one direction relative to said carrier position control member, spring means normally positioning said escapement pawl means in operative engagement with said carrier position control member for resisting movement of said carrier by said urging means, and wherein: said second operating means comprises means for separating said pawl means from said carrier position control member. 